Knuckle stun gun



FIG. 1 is a front perspective view of a knuckle stun gun showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a right side elevational view thereof; and,

FIG. 7 is a left side elevational view thereof.

The broken lines in FIGS. 1-2 and 4-7 illustrate portions of the knuckle stun gun that form no part of the claimed design. 

CLAIM The ornamental design for a knuckle stun gun, as shown and described. 